Liquid fuel burning apparatus



Sept. 20, 1938. M. A. POWERS 1 LIQUID FUEL BURNING APPARATUS Filed Aug. 20, 1934 2 Sheets-Sheet 1' Elma/rm 4/17/00 A %ners ham 5 Gum/M013 Sept. 20, 1938.

M. A. POWERS LIQUID FUEL BURNING APPARATUS Filed Au 20, 1934 -2 Sheets-Sheet 2 3mm Mi/fan A. Power;

away/ W Patented Sept. 20, 1938 PATENT OFFICE...

2,130,471 v LIQUID FUEL BURNING APPARATUS Milton A. Powers, Detroit, Mich, asslgnor, by

mesne assignments, to The Timken-Detroit Axle Company, a corporation of Ohio Application August 20, 534 Serial No. 740,698 '3 Claims. (Cl. 158-77) This invention relates to a novel apparatus for burning liquid fuel in accordance with what has come. to'obe known recently as the wall flame principle. More specifically, the invention relates to rotary power burners for use in small installations, such as hot water heaters.

In most cases in the prior art the rotating parts of rotary oil burners are separately assembled and are of considerable size and weight. This necessitatesconsiderable power for their operation, and it is evident that high stresses are inherent due to the centrifugal forces set up as r a result of which the parts must be made extremely rigid. Perhaps for this reason, in many prior devices fuel oil is supplied at approximately the level at which it is to be discharged so that additional work will not be required of the operating'motor. However, in order to supply the fuel oil at this point, it is necessary in many' installations to have a special device to perform this one function. It is highly desirable to use a single motor to perform all the work.

The rotating parts of my device are assembled as a unit and are of relatively small diameter so that the centrifugal force developed'thereby is negligible, which permits the use of very light parts. Consequently, the power required to rotate such parts is exceedingly small, and I am able to use a relatively small operating motor both for this purpose. and to raise the fuel oil to the level at which it is to be discharged. Therefore, one of the principal objects of .this invention is to provide a rotary oil burner having small parts of light weight and operated with a minimum of friction'by a relatively small motor.

Conventional oil burning systems ordinarily have two, types of control sets. One set may be termed temperature controls, and the other, safety controls. The former govern the normal operation of the system and depend for their operation on the temperaturesof the water, air,

or whatever is heated by the flame. The lat-- ter govern the safe operation of'the system, and operate only when there is a failure of some part ofthe system to operate normally. Prior rotary power burners have embodied a multiplicity of such controls in order to insure safe and positiveoperation, such as complicated magnetic oil.

valves, stack temperature-operated electric shutv of]? switches and myriads of other electrical devices. -In other words, complicated systems have been set up to insure safe operation. In my invention'I have discarded such complicated systerns. I have made the fuel the safetycontrol of the system and have simplified it to the ex- .combustion chamber.

- onthe line 2 2 of Figure 1, and

stop, no fuel oil will be raised to the discharge 5 leveland no combustion will take place.

Therefore, another of the principal objects of this invention is to provides. rotary powerburner with a simple, positive safety control system. More specifically, it is an object to devise a novel 10 means whereby the flow of fuel in and of itself operates to stop operation of the burner.-

A further object is to provide a doubly-safe control system whereby the flow of fuel' may be stopped by devices in the fuel circuit in either 1 or 'both sides of the burner fuel inlet and/or outlet. More specifically in this connection it is an object to provide an oil shut-off device which connects with the oil feed line and also with the 20 A further object is to provide arotary fuel burning system which will operate safely with only one thermostatically-controlled electric switch.

A further object of this invention pro- 25 'vide a liquid fuel burner in which the flow of fuel from the source of supply is automatically cut off upon failure of the liquid level valve to function .or upon failure of the burr r to ignite.

Another object of the present invention is to provide a control system for a liquid fuel bumexpensive-easy to install and economical and 40 safe to operate.

The foregoing and further objects of the invention will fully appear from astudy of the following details and descriptionwhen taken in conjunction with the accompanying drawings. Referring now to the drawings wherein like numerals are employed to designate like parts wherever they occur,

Figure 1 is a vertical sectional view of a preferred embodiment of my-invention taken on the line l-l of Figure 2. It shows the oil meter- 7 ing and level valve out of position for the sake of clarity. I s

Figure 2 is a horizontal sectional view taken h D u smooth surface.

'tloned portion is a space 31 formed by an up-' Figure 3 is an enlarged sectional view showing the oil drain outlet at the hearth, as seen on the line 3-3 in Figure 2.

The complete burner A is mounted centrally in a combustion chamber 0 with its oil delivery level approximately on a level with the lower portion of the water legs of water heater D, which is supported on a base B. Oil is supplied to the burner from a conventional storage tank to an oil metering and constant level valve F, and thence to the burner A.

Referring particularly to Figure l, the oil and air supply mechanism proper consists essentially of a stationary portion I and a rotating portion 2. Said stationary portion consists of an outer casing 4 of cuplike section having an upstanding central boss 6 therein. Approximately midway down the inner surface of said casing 4 is placed the stator portion 8 of the propellin electric motor. Said stator portion 8 is suitably positioned and retained in casing 4 by being press-fitted into a cylindrical surface and against a shoulder provided therefor in said casing. The stator embodies coils 9 which are so disposed as not to interfere with the type of air circulation hereinafter described. i

The upper portion of said casing has a series of apertures i0, extending intermittently around the outer periphery for the purpose of admitting air. Placed around said apertures l0 and located in a groove i5 provided therefor in casing 4 is an air shutter I l for the purpose of controlling the air supply. The air, that is thus supplied for combustion, serves during its passage to cool the motor, particularly the windings 9 thereof. Said shutter is provided with ears i2 at its ends, which may be clamped together by means of screw l4, in order to lock said shutter in place. A series of lugs H are provided on the outer periphery of easing 4 approximately midway its height, said lugs being apertured to receive bolts for bolting said burner in position.

The central upstanding boss 6 has a tapered aperture extending through the bottom of casing 4 for the purpose of press-flttedly receiving a bronze sleeve 22. Said sleeve has an aperture running therethrough, the upper portion 24 of which is of a lesser diameter than the lower portion 25. The lower extremity of portion 25 is suitably threaded to' receive a special screw 26 which seals said extremity by means of clamping packing 28 between the screw head and the lower end of said sleeve. Mounted on top of screw 26 and within portion 25 is a hardened plug 30 which is substantially cylindrical in shape and for a purpose to be described later.

A chamber sealed at its lower portion thus is formed on the inside of sleeve 22. This chamber is utilized as a lubricant reservoir to insure lubrication of a rotating shaft to be described later.

The outside diameter of sleeve 22 above the tapered portion is of uniform size and of a .Surrounding' said last-menstanding cylindrical extension of upstanding boss 8 which likewise has smooth inner andouter diameters of uniform size. Fuel oil is admitted to saidspace 81 by means of aperture 40 which connects with the outer periphery of easing 4 and passage 42. Fuel oil is supplied to aperture 40 from valve F.

The rotating portion 2 of the distributing head includes an armature or rotor 46 whichis attached as a unit on a casting 50. Casting 50 has a lower cylindrical portion which is in- -52 and disposed at an angle therewith are two diametrically opposite apertures and have pressfltted therein the lower ends of several oil flinger tubes 58. Said flinger tubes are bent at the upper extremities to form nozzles 60. The upper portion of sleeve 22'has a reduced diameter to afford more space to accumulate fuel oil which has previously been raised by means of threads 52.

Extending centrally through an aperture provided therefor in casting 50 and in press-fitted engagement therewith is shaft 62 having its lower portion hardened and ground. Said shaft has in its lower portion a shallow hole which is so sized as to rotatably receive a hardened ball 56.

Shaft 62 is so positioned with respect to casting 50 that when the rotating portion 2' is lowered I so that ball 66 rests on hardened block 30, arma ture 46 will be in register with stator 8, the upper surface of cylindrical portion 38 will clear the registering portion of casting 50 and the lower surface of cylindrical portion 5| will not abut the lower surface forming space 31. The shaft 62 and casting 50 of course rotate in unison. In this manner, the rotating portion 2 is supported solely upon hardcnedblock 30 so that the only friction resisting turning of said rotating portion results from the contact of ball 66 with hardened block 30 and the friction of shaft 82 within aperture 24 of sleeve 22.

A fan 10 is provided on the upper portion of shaft 62 and consists essentially of a disk I2 of sheet metal havingat its central portion a plug 14 shear-riveted in place as at 16. Said plug 14 is centrally apertured to receive shaft 82 and is provided with a set screw 18 for the purpose of positioning said fan 10 in the proper vertical relation to shaft 62 and nozzles 60. Spot-welded to the underside of metal disk I2 is a series of fan blades 80. It is understood that the invention is not to be restricted to the particular fan head described, as any suitable form may be used.

The parts above described in detail are shown in assembled and running position in Figure 1. The entire mechanism is bolted to a lower metal hearth plate 82 by means of bolts Bi passing through apertures provided therefor in the lugs l1. Packing 84 is provided between the upper cylindrical surface of casing 4 and hearth plate 82 as a means of insulating against excessive heat and preventing air leaks.

The hearth assembly in which the distributing mechanism is placedis very similar to that described in my co-pending application Serial No. 729,928, filed June 9, 1934. Itconsists of the lower hearth plate 82, the layer of insulation 83 on top thereof, said plate 82 and insulation 43 being bolted to an internal flange 85' provided therefor on the heater-base B by means of bolts 86; and an upper metal hearth plate or hearth proper 88, which is spaced from the lower hearth 82 by means of spacers 90. Said spacers are of channel section and have apertures 92 in their vertical surface for the purpose of ventilation. Said spacers are spot-welded to upper hearth plate 88 and are secured to lower hearth plate 82 and insulation 84 by means of bolts 9|.

A further spacer 94 of cylindrical form is placed between the hearths 82 and 88 at their center portions, said upper and lower hearths 88 and 82 respectively having central apertures of a size equal to the inside diameter of spacer 84. Upper hearth 88 is lipped upwardly as at 96 around its central aperture. flanged cylindrical member 98 which flts snugly inside of spacer 94. In assembly, said member 98 is inserted after spacer 94 has been inserted between the upper and lower hearths. The lower portion of said member 98 is then peened or bent, over and around the underside of the aperture through lower hearth 82. In this manner member 98 is retained in place and at the same time retains spacer 94 and insures the relative spacing of the upper and lower hearths. The peripheral its age of member 98 extends to a diameter very nearly. equal to the outer diameter of fan blades 89. This prevents recirculation of the air through the fan.

Upper hearth 98 has at its outer periphery an upstanding flange 89 for the purpose of collecting any moisture or unburned fuel which may drop from the combustion chamber wall so that it may be evaporated, or burned, as the case may be, when the temperature becomes high enough. In close proximity to the outer periphery of the combustion chamber is a series of three continuous rings, each formed in one piece or strip of sheet metal, and comprising: an air deflecting ring I99, nearest the burner head, and of the least height; an oil impingement and vaporizing ring I92, of greater height; and an outer ring I94, of the greatest height. The one piece rings I99 and I92 flt snugly upon the hearth plate 88 to form a sheltered gutter or ignition groove I9I. As before stated, said rings are continuous and are positioned with respect to each other and upper hearth plate 88 by means of L shaped pieces I96 which are spot-welded to said rings and hearth plate. Outer ring I94 also flts snugly on the hearth plate 88 and may be termed a splash ring as it is for the purpose of conflning any fuel oil which may splash from impact ring I92 within the combustion zone. An igniter I I9 is provided adjacent and inwardly of ring I99 and is generally of the type disclosed in my previous application Serial No. 731,562, flied June 29, 1934.

The front portion of the heater base .8 is rectangularly bulged to provide for the insertion of the burners component accessories. The forward side of said bulge is open, having a screen or perforated sheet cover I98. Said accessories consist essentially of oil metering and level valve assembly F, oil sump and air trap G, and a transformer and condenser (not shown). A bracket H2 is suitably provided to position oil metering and level valve assembly F and is so positioned that the oil level of said Valve assembly-as indicated at I I4 in Figure 1-is at the correct height to insure the lower portion of threads 52 of rotating portion 2 being below said oil level line.

There is no novelty claimed for the oil metering and level valve structure per se, as it is of conventional type, having an oil inlet III! and outlet I I3, and as any known device having the proper characteristics will sufllce, a fully detailed showing is unnecessary. However sumcient disclosure will be made to clarify the operation. With particular reference to Figure 1, oil passes from the inlet H5 through the usual oil strainer portion III into a chamber or reservoir contain- Resting on said lip 99 is a ing a float II8. By means of a lever H9 the float is connected to a valve I29 which is designed to move vertically to control the upper end of a passage I2l through which oil normally is discharged to the metering portion I22 of the assembly.

, The upper end of passage I2I is located below the horizontal plane of line II4, previously mentioned, and adjacent thereto and slightly above said plane a lip I23 is provided. The float and lever are designed to close the valve when the oil level tends to exceed that of the plane II4 but if for any reason the float chamber fills to a level.

spring cooperates with the lever to yieldingly re-- sist downward movement of the trip bucket. It will prevent the bucket from dropping until a predetermined quantity of oil has been discharged into the, bucket to overcome the spring resistance.

-In its descent the bucket pulls the lever I26 into contact with the upper end of valve I29 to force the latter into a sealing seat in the upper end of the passage I2I and thus positively cut off the oil supply through the metering valve to the burner.

The oil metering valve per se (not shown) is of any conventional type for permitting a predetermined maximum flow of oil from passage I2I into the outlet II6 for transmission to the oil reservoir 31 of the motor assembly. It is associated with a shaft I3 9 having a wing nut I3I attached thereto. The quantity of flow of oil is governed by rotating said wing nut to a position which gives the desired rate of fuel flow.

A drain pipe I32 is connected at one end with a drain hole I 33 provided in the upper hearth plate 88 (see Figures 2 and 3). This drain hole may be located entirely between the rings I99 and IN, or entirely inwardly of the ring I99; but preferably as illustrated in Figure 3 it is bisected by the ring I99so that it will drain oil from both the gutter IM and the hearth portion inwardly of said gutter. Immediately surrounding said drain hole,

the hearth plate 88 has a circular raised portion portion. The lower edge of the ring I99 is notched where it passes over this raised portion. In practice the distance of the top of raised portion I34 above the top of hearth plate 88 is approximately for the following reason. It is evident that when'the burner starts up cold, all of the fuel flung outwardly from flinger tubes 58 will not be immedaitely consumed. If the surface surrounding drain hole I 33 were not raised, such fuel would immediately. drain through pipe I32 and cause the liquid in sump G to overflow into trip bucket I24, thus causing premature shut down. By having portion I 34 raiseda short distance the burner is given a chance to -get started, for a certain amount of fuel will have to accumulate before overflow can occur.

The connection between the receiving end of pipe I32 and the port I33 comprises a cylindrical sleeve I39 inserted upwardly through holes provided therefor in lower hearth plate 82 and insulation 83. The upper portion of said sleeve is press-fitted around depending lip portion I35 and elbow is connected at its other end with drain pipe I32. The parts are so arranged that drain pipe I32 slopes downwardly from its connection with elbow I31 to its connection with sump G.

The sump or air lock G is suitably placed adjacent the trip bucket I24, and is provided with a suitable means (not shown) for retaining it so emplaced. Said sump G is substantially cylindrical in shape, having a top and a bottom, and an internal bafile I38 diametrically placed and extending from the top to a point more than half way down its height. On one side of said bafile and adjacent the top of the sump is a boss having a threaded aperture which receives the threaded outlet end of drain pipe I32. otherside of baffle I38 and diametrically opposite the outlet end of pipe I32 is a spout or lip I39 which terminates above the trip bucket I24. When installed in place the sump G is filled with oil or other liquid. It is evident then, that no air can leak past baffle I38 into the combustion chamher in a direction reverse to the path of overflow oil,or, in other words, an effective air lock is formed. Any oil discharged over the lip I39 will accumulate in the bucket I24 and eventually trip the latter and thus close the float valve.

There are therefore two safety means of stopping the burner operation should failure of any of the parts occur. The first is in the oil metering and level valve assembly F which prevents the level of the oil exceeding a certain predetermined height, and the second'is the overflow system It may be desirable to impart a slight down-- ward slope to. the upper hearth plate in the direction of the drain hole I33 so as to prevent any excessive accumulation of oil on the hearth prior to discharge of said accumulation through the drain pipe. A suitable method of providing the desired slope is to so cast the base B that the lower face of its hearth-supporting flange 85 will be gradually inclined downwardly toward the hole I33 from the side diametrically opposite said hole. The hearth plate 88, which is parallel to said lower face, thus will be given a corresponding. inclination which, in practice, will be about.% to inch.

In the corner of the bulge portion of the base casting opposite to that containingvalve assembly F, is the transformer H. Said transformer is bolted to said base casting by means of suitable bolts I. Said bolts I also perform the function of a ground connection.

Referring now to the electrical circuit, a suitable source of electricity is provided and a conventional switch is provided between the source and all other electrical devices, said switch being thermostatically controlled by a suitable thermostat T placed in the water chamber of the heater. (See Fig. -1.) When the water in the heater has reached a certain predetermined tem perature the thermostat functions to open the electric switch and thus stop the operation of the controlled switch will be closed, and-when the usual main control switch (not shown) is snapped on, current flows into the transformer and the ,motor' of the burner assembly A. A spark immediately'beglns to jump from electrode I50 to ring I02, and also, the rotary portion 2 of the-burner A starts rotating. The oil line from the reserve On the tank E to the burner A is always open unless closed by trip bucket I24. The valve assembly F maintains the oil at the level of line II4 so that the lower portion of threads 52 of rotating portion 2 are always immersed for about of their length. As soon as the portion 2 starts revolving, the threads 52 will carry the oil upwardly and when it reaches the upper portion of said threads, due to centrifugal force, will divide equally, half going into each flinger tube 58 and thence being flung outwardly from each nozzle 60. Said oil flies toward the impact ring I02 and upon impact therewith is shattered into smaller particles. Air

is supplied through apertures I0 of burner A and is carried upwardly through the center orifice formed by member 98, and is then forced outwardly by fan blades 80. The air strikes the ring I00 and is deflected upwardly and outwardly,

.a portion of it admixing with the oil particles,

thus forming a combustible mixture in the groove or gutter formed by impact-ring I02, hearth 88 and ring I00. Initial combustion takes place in said groove by means of the spark created across the spark gap. The groove is deep and forms an excellent area for flame propagation. As soon as the rings become heated, the impinging oil is completely vaporized, and the flame rises and licks the periphery of the combustion chamber. The flame also heats the outer surface of the ring I02 to render the entire ring intensely hot and capable of instantaneously vaporizing all impinging oil.

The metering device, previously described and which is controlled by wingnut I3I, is necessary to provide for different operating conditions. Should the ignition fail at any time, the oil return pipe I32 will provide for draining off the unburned oil and cause it to flow into the trip bucket I24, which will immediately stop the supply of oil. In like manner, should the constant level part of the valve assembly F get out of order in any way, the trip bucket will operate to stop the flow of oil. The motor will continue to operate and current will continue to flow through the transformer should the trip bucket for any reason he tripped. This, however, is not serious as the amount of current required is almost negligible and the fact that' the'burner is not doing the work it-is supposed to be doing, will very soon be noticed.

The only wearing surfaces of the burner are the lower portion of shaft 62 and the portion 24 of sleeve 22. An extremely long bearingas compared to the diameter-is provided between these surfaces which is conductive to low unit stresses.

' Thrust ball 66 carries only the weight of the parts comprising rotating portion 2 and inasmuch as it is constantly bathed in oil, its wear is negligible.

Therefore, my invention comprises an extremely emcient burner having few parts and which requires a minimum of associated devices for its safe and efficient operation. Servicing of this burner is exceedingly simple. The removal of cover I08 gives access to all of the associated parts and the removal of the rotating portion 2 of the burner proper is accomplished merely by reaching in through the fire door and lifting It out.

It is interesting to note that the operation of this burner is based in great part upon the physical law that liquids seek their own levels. Thus, the level of the fuel oil in the burner is maintained equal to.the controlled level in the valve assembly F; and in the oil sump G the level of the oil on one side of the baiile I38 remains the some ,Just described the heater unit is so constructed and assembled that one of its internal parts forms a combustion chamber for special close cooperation with the burner assembly, and comprises the following parts,described without adhering to the manner or order in which they are put together.

A pair of concentric cylindrical shells, I55 and "I, are spaced by a ring I51 to which the fdrmer is welded adjacent its lower edge. The ring and the outer shell rest upon a circular gasket I58 carried by base flange 85, the latter and the ring being so shaped and of such size that when the burner assembly is added the hearth rim 89 will be disposed beyond the periphery of the shell iii and close to the lower edge thereof, as seen in Figure 1. An integral upstanding flange E60 is formed on the base flange 85, this flange being larger in diameter than the shell I56 to permit a free fit under all conditions. The annular space between these two members is then packed with furnace cement, as at I62.

The inner shell I55 is very short in height and is capped by a dome plate I63 provided with a rim H88 which fits snugly within the upper end of the shell and is welded thereto, as shown. The shell and plate thus produce an inverted cupshaped member which forms the combustion chamber C. A relatively small flue or pipe I65 is welded at its lower end to the center of the dome plate I63 and extends vertically upwardly for cooperation with any suitable further structure to form a water chamber I61.

As the height of the combustion chamber C is considerably less than the diameter of the hearth, and as the chamber is provided with a relatively small outlet, centrally located, an exceptionally high degree of efficiency is obtained. This is particularly true where, as illustrated, the

burner assembly is of the rotary wall flame type. 7

with combustion taking place at the periphery and the low dome I63 serving to hold the flame down while being licked thereby to develop temperatures causing very rapid transfer of heat to the water. To further prevent the flame from elongating and-tending to run into the small central outlet. am overhanging grillwork (not shown) will be mounted on the oil vaporizing ring I02. As another example, the grillwork may be formed by utilizing a-ring In of greater height than that here shown, with its upper edge turned inwardly to overhang the gutter and provided either'with simple perforations or with spaced upright vanes struck out from the material to afford spaced slots. Likewise the ring I94 might be modified insimilar fashion.

It is understood that, although the invention is disclosed in connection with a hot water heater, it is not to be so restricted, as it may be used with other heating devices. The invention consists principally in the burner mechanism and its asaociated parts.

The invention may be embodied in other speciflc forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:-

1. In a liquid fuel burning apparatus of the type comprising a combustion chamber closed at the bottom by a substantially horizontal hearth and embodying means for conveying liquid fuel into the chamber and projecting it in liquid form substantially horizontally over the hearth; a fuel impact wall arranged in the path of the projected liquid fuel; means cooperating with said wall to form a gutter for collection of unconsumed fuel; means for removing any excess of unburned fuel from the chamber, said means being in communication with said gutter, and also with the upper hearth surface at a point outside the gutter; and

-means cooperating with said removing means to stop the liquid fuel projection in response to discharge of a predetermined quantity of unburned fuel from said hearth and said gutter into said removing means. I

2. In a liquid fuel burning apparatus of the vtype comprising a combustion chamber closed at the bottom by a substantially flat sloping hearth and embodying means for projecting liquid fuel into the chamber, said hearth being providedwith an overflow port adjacent the lower side thereof with its overflow edge raised slightiy above. the hearth surface surrounding the port, said hearth having suflicient slope from one side to the'other in the direction of said overflow port to ensure full drainage into said port the hearth being otherwise closed around the fuel projecting means to collect and hold some imburned liquid fuel, means for receiving unburned liquid-fuel discharged through said port, andmeans cooperating with said receiving means to interrupt the projection of liquid fuel into said combution chamber when a predetermined quantity of liquid fuel has passed over said-overflow edge of the portfor drainage into said receiving means.v a

.3. In a liquid fuel burning apparatus of the type comprising a combustion chamber closed at the bottom by a substantially horizontal hearth and embodying centrally disposed means for projecting liquid fuel into the chamber, said hearth being provided with an overflow port adjacent the periphery thereof, said hearth having sufficient slope from one side to the other in the I direction of said port to ensure fuel drainage into the port without accumulation of excessive unburned fuel in the chamber, and means for receiving the liquid fuel discharged from said port and for interrupting the fuel projection upon receipt of a predetermined quantityv of the discharsed uel.

umrou s. .ro'wnae. 

